选择要带回ORACLE SQL的值列表的情况

SELECT employee_name
FROM employees
WHERE department_id = (
  SELECT department_id
  FROM departments
  WHERE department_name = 'IT'
);

SELECT customers.customer_name, orders.order_number
FROM customers
JOIN orders ON customers.customer_id = orders.customer_id;

SELECT employee_name
FROM employees
WHERE department_id IN (
  SELECT department_id
  FROM departments
  WHERE department_name IN ('Sales', 'Marketing')
);